Nitrate containing vegetables and dietary nitrate and nonalcoholic fatty liver disease: a case control study

Vegetables is the main sources of dietary nitrate. Studies suggested the potential link between nitrate content of vegetables and reduce the risk of chronic diseases. We aimed to assess the association between nitrate-containing vegetables (NCVs) with odds of nonalcoholic fatty liver diseases (NAFLD) in Iranian adults.

This case-control study was performed on a total of 225 newly diagnosed NAFLD cases and 450 controls aged 20-60 years. Individuals' dietary intakes were determined using a valid and reliable food frequency questionnaire.

The mean ± SD age and BMI of participants were 38.1 ± 8.8 years and 26.8 ± 4.3 kg/m², respectively. In the fully adjusted model, the odds of NAFLD were decreased across tertiles of total NCVs [(adjusted OR: 0.20, 95%CI: 0.10-0.40), (P_trend <  0.001)] and low-nitrate vegetables [(adjusted OR: 0.22, 95%CI: 0.11-0.48), (P_trend <  0.001)]. Our results showed that each one SD increments in nitrate content of vegetables (adjusted OR: 0.73, 95%CI: 0.55-0.97) and nitrate content of fruits (adjusted OR: 0.59, 95%CI: 0.36-0.97) was associated with reduced odds of NAFLD (P <  0.05). However, there was a positive association between each one SD increments in nitrate content of dairy products and meats and processed meats with odds of NAFLD (adjusted OR: 1.34, 95%CI: 1.03-1.74), (P <  0.05).

Our finding suggested that a higher intake of vegetable nitrate may be related to a decrease the odds of NAFLD.